1. Field of the Invention
The present invention relates to a structure of an ink-jet recording apparatus permitting at least one ink cartridge mounted thereon to be replaced, and more particular to a structure of an ink cartridge holding device which holds the at least one ink cartridge.
2. Discussion of Related Art
In an ink-jet recording apparatus, an ink droplet or ink droplets are selectively ejected from a recording head onto a recording medium, e.g., a recording sheet, based on an image data, so that an image is recorded on the recording medium. In the ink-jet recording apparatus described above, ink is normally pre-stored in a cartridge-type ink tank (hereinafter, abbreviated as “an ink cartridge”), and supplied from the ink cartridge to the recording head. Generally, the ink cartridge includes a cartridge body and an ink preserver as ink preserving means which is contained by the ink cartridge body. On the cartridge body, there are provided an ink supply portion for supplying the ink to the recording head and an air introducing portion for introducing air into the ink cartridge. In order to avoid evaporation or leakage of the ink in a state in which the ink cartridge is not being attached to the ink-jet recording apparatus, each of the ink supply portion and the air introducing portion is closed by a valve mechanism or a sealing member which is provided for sealing the same.
Generally, depending on a manner of supplying the ink from the ink cartridge to the recording head, types of the ink-jet recording apparatus are roughly classified into following two types: so-called an “ON carriage type” and an “OFF carriage type”. In the ink-jet recording apparatus classified as the “ON carriage type”, a case for holding the ink cartridge is directly mounted on a carriage which is equipped with the recording head and which is reciprocatable above the recording sheet. The ink cartridge is attached to an ink cartridge attaching portion (hereinafter, abbreviated as an “attaching portion”) provided in the case. More specifically, an ink supply needle which is provided in the attaching portion of the case is connected to the ink supply portion of the ink cartridge, whereby the ink is supplied from the ink cartridge to the recording head.
In the recording apparatus classified as the “OFF carriage type”, the ink cartridge is disposed on a portion located inside or outside of a body of the ink-jet recording apparatus. In this arrangement, the ink cartridge is connected, via a flexible ink supply tube, to the recording head in full time, so that the ink is supplied from the ink cartridge to the recording head. Further, there is another “OFF carriage type” ink-jet recording apparatus in which the ink cartridge is temporarily connected to the recording head via connecting means provided on a specific position in the ink-jet recording apparatus when the recording head is moved to the above-indicated specific position, so that the ink is supplied from the ink cartridge to the recording head. It is noted that, in order to simplify a description, an “OFF carriage type” ink-jet recording apparatus to be described hereinafter is classified as the above-described “OFF carriage type” in which the cartridge is connected, via the flexible ink supply tube, to the recording head in full time, so that the ink is supplied from the ink cartridge to the recording head.
In the above-described ink-jet recording apparatus classified as the “OFF carriage type”, there is provided an accommodating portion for accommodating the ink cartridge, usually having a case which is provided therein for holding and stabilizing the ink cartridge. Inside of the case, there is provided the attaching portion which has the ink supply needle. The ink supply needle is connected to the recording head via the ink supply tube, etc. Further, in a state in which the ink cartridge is attached to the attaching portion provided inside of the case, the air introducing portion is opened and the ink supply needle is connected to the ink supply portion of the ink cartridge. The air is allowed to be introduced into the ink cartridge while the ink is allowed to be supplied from the ink cartridge to the recording head owing to the arrangement in which the ink supply portion is connected to the ink supply needle.
In this arrangement, the ink cartridge and the case are pre-constructed together as a unit which is to be slot into the above-described accommodating portion of the ink-jet recording apparatus. The unit is particularly defined as a “refill unit”. The case of the refill unit has a door, in general. The door is to be closed in a state in which the ink cartridge is accommodated in the case. Owing to this arrangement, the ink cartridge is reliably accommodated in the case. When the ink cartridge is replaced, the door is opened so as to permit the ink cartridge to be removed from the case.
If temperature and atmospheric pressure at a time in which the ink cartridge is taken out from a package is different from the temperature and the atmospheric pressure at a time in which the ink cartridge is manufactured, sometimes internal pressure of the ink cartridge may be increased. If the above-described ink cartridge with the high internal pressure is attached to the attaching portion of the case, there is a risk in which the ink is spout out from the air introducing portion and/or the ink supply portion because the internal pressure of the ink cartridge tries to be equal to the atmospheric pressure.
As disclosed in Japanese Unexamined Patent Application Publication Nos. 2006-94710, 11-129492, and 9-207347, the internal pressure of the ink cartridge is set as a negative pressure at a time in which the ink cartridge is manufactured in order to obviate a leakage of the ink.
However, when the ink cartridge with the negative pressure is attached to the attaching portion, there is a risk in which the air is sucked from the recording head into the ink cartridge if the ink supply portion is connected to the ink supply needle before the air introducing portion is opened. If the air is sucked from the recording head, wastes which are adhered to the recording head, such as dried-up ink, may be also sucked together with the air. Moreover, air bubbles may be generated in the recording head if the air is sucked from the recording head. The above-described situations may cause a bad ink ejection, and moreover, cause an unstable quality of recording.
Therefore, the air introducing portion needs to be opened before the ink supply portion is connected to the ink supply needle. More specifically, the ink supply portion needs to be connected to the ink supply needle after the air introducing portion is opened such that the internal pressure of the ink cartridge is equal to the atmospheric pressure.
According to construction of the ink-jet apparatus disclosed in the Japanese Unexamined Patent Application Publication No. 2006-94710, as shown in FIG. 22, followed by a pushing movement of a presser lid 246 (a door), a vent hole film 234 is pierced by a hollow needle 251 such that a vent hole 230 (an air introducing portion) is opened to the atmosphere before a cover film 226 covering an ink outlet 223 (an ink supply portion) is pierced by a head needle 242 (an ink supply needle) such that the head needle 242 is connected to the ink outlet 223. More specifically, the ink outlet 223 is formed in a bottom end portion of an ink cartridge 203 and the vent hole 230 is formed so as to open to an upper surface thereof. Further, the cover film 226 and the vent hole film 234 are heated and pressed so as to be bonded to the ink outlet 223 and the upper surface, respectively. The ink cartridge 203 can be inserted into and withdrawn from a cartridge holder 243 (a case) which has a case-like shape. Inside of the cartridge holder 243, there is disposed the head needle 242 which is connected with a print head 241 (a recording head), as shown in FIG. 22. Further, on an upper portion of the cartridge holder 243, there is provided the presser lid 246 which is opened and closed by pivoting about a support shaft 245. The hollow needle 251 which breaks through the vent hole film 234 is set in the presser lid 246,
Initially, the hollow needle 251 sticks and pierces the vent hole film 234 so that the vent hole 230 is opened to the atmosphere as the presser lid 246 is closed. Subsequently, the head needle 242 pierces the cover film 226 so as to be connected to the ink outlet 223 as the ink cartridge 203 is further pushed by the presser lid 246, as shown in FIG. 22.